In a storage system Input/Output or I/O request refers to the communication between a storage device and the host system. The host will typically make I/O requests to the data storage subsystems. The inputs are signals or data received by the storage system, and the outputs are signals or data sent by the storage devices. For efficiency each host can accumulate a batch of I/O requests from users and transmit them to the data storage subsystem. When a storage device is serving multiple hosts quality of service (QoS) in terms of performance delivered to the host may vary depending on the overall load on the storage device. There have been multiple implementations to deliver different QoS to different workloads using various scheduling algorithms such as a deadline scheduling algorithm.
Other features of the present embodiments will be apparent from the accompanying drawings and from the detailed description that follow.